Steinernema riobravis Cabanillas, Poinar & Raulston, 1994, Thermo Trilogy strain (Nematoda, Steinernematidae) was the nematode species used for application to small-scale field against Neocurtilla claraziana (Saussure, 1874) (Orthoptera, Gryllotalpidae), a pest of soil in three gardens of Gran La Plata, Argentina. Assays were performed with dosages of 6,000, 10,000, 20,000, 40,000 and 80,000 nematodes per 3 m2, with a density of 32 ± 7 mole crickets/3 m2. The application was performed with hand sprayer. The percentages of effectiveness varied in different gardens, the first lower dose was 65% ± 15.67 and the highest dose was 83% ± 22.25, with ± 80% being the average dose 18.56. For the second garden 50% ± 8.31 for the low dose and 76% ± 21.15 for medium and higher, and for the third garden the lower dose was 42 ± 15.87%, the highest dose of 66% ± 18.32 and the mean dose of 60...

Hexamermis bonaerensis sp. n. a parasite of Epilachna paenulata (Germar, 1824) (Coleoptera, Coccinellidae) from Argentina is described. It is characterized by having the amphids medium sized, rounded oval shaped, the vagina muscularized and slightly protruding with a descending branch forming a loop before joining the uterus. It presents three rows of genital papillae: the ventrolateral in one row with thirteen papillae; the ventral row with two single, three pairs and two single preanal papillae, and with five pairs postanal papillae. Publicación registrada en Zoobank:LSIDurn:lsid:zoobank.org:pub:9F5EA90D-381D-4FC8-8F0F-86B9E1D2F014 Acto nomenclatural:LSIDurn:lsid:zoobank.org:act:35252E81-2E50-4F12-94DF-FC3617971627

Hexamermis bonaerensis sp. n. a parasite of Epilachna paenulata (Germar, 1824) (Coleoptera, Coccinellidae) from Argentina is described. It is characterized by having the amphids medium sized, rounded oval shaped, the vagina muscularized and slightly protruding with a descending branch forming a loop before joining the uterus. It presents three rows of genital papillae: the ventrolateral in one row with thirteen papillae; the ventral row with two single, three pairs and two single preanal papillae, and with five pairs postanal papillae. Publicación registrada en Zoobank:LSIDurn:lsid:zoobank.org:pub:9F5EA90D-381D-4FC8-8F0F-86B9E1D2F014 Acto nomenclatural:LSIDurn:lsid:zoobank.org:act:35252E81-2E50-4F12-94DF-FC3617971627

Two new species nematodes (Thelastomatidae) are described. Both parasites of the wild cockroach Blaptica dubia Serville, 1839 (Blattodea, Blaberidae), found in the Horticultural Belt of La Plata, Argentina. Thelastoma simplex sp. n. is characterized by small, pear-shaped amphidia, cuticularized stoma, no teeth, nerve ring anterior to the basal bulb, excretory pore is situated between basal bulb and beginning of the intestine, vulva protuberant in half of body, muscular vagina, amphidelphic, with anal wing and a very long, threadlike caudal appendage. Males with spicules on anal promontory accompanied by a thick, strong gubernaculum, genital papillae in three simple preanal papillae, of which the first is very large, adanal pair and a simple postanal at base of caudal appendage. Blattophila incomptus sp. n. has short stoma with plate and two teeth, large amphidia, excretory pore near base...

Presence of the genus Neoparasitylenchus Nickle, 1967 (Tylenchida, Allantonematidae), parasitizing Harmonia axyridis (Pallas, 1773) (Coleoptera, Coccinellidae) in Argentina. We describe a new species Neoparasitylenchus platense sp. n., which is characterized by having the free living stages lip region flatly rounded, spear slender, faintly knobbed, tail rounded, females with light brown body, stylet not sunken into body, and not prominent, subterminal vulva and anus, obtusely rounded tail end, with a peg-like projection, oviparous, and the males with a little stylet and partially degenerate oesophagus, spicules filiform with widened base, short gubernaculum, leptodera bursa. ________________________________________________________________Publicación registrada en Zoobank/ZooBank article registered:LSIDurn:lsid:zoobank.org:pub:FBE9DC98-04C4-4074-9037-1F5979320E2FActo nomenclatural/nomenc...

Presence of the genus Neoparasitylenchus Nickle, 1967 (Tylenchida, Allantonematidae), parasitizing Harmonia axyridis (Pallas, 1773) (Coleoptera, Coccinellidae) in Argentina. We describe a new species Neoparasitylenchus platense sp. n., which is characterized by having the free living stages lip region flatly rounded, spear slender, faintly knobbed, tail rounded, females with light brown body, stylet not sunken into body, and not prominent, subterminal vulva and anus, obtusely rounded tail end, with a peg-like projection, oviparous, and the males with a little stylet and partially degenerate oesophagus, spicules filiform with widened base, short gubernaculum, leptodera bursa. ________________________________________________________________Publicación registrada en Zoobank/ZooBank article registered:LSIDurn:lsid:zoobank.org:pub:FBE9DC98-04C4-4074-9037-1F5979320E2FActo nomenclatural/nomenc...

Protylenchus bonaerensis n. sp. (Tylenchida, Allantonematidae) was found in the Horticultural Belt of Gran La Plata, Argentina. This genus is reported for the first time in our country and a new species is described parasitizing adults of Harmonia axyridis (Pallas, 1773) (Coleoptera, Coccinellidae). This new species is mainly characterized by the males having a thin bursa, females with a non-protuberant vulva, and a short and thin caudal appendage in both sexes. In addition, the life cycle is described.  

A new species Proparasitylenchus inalienatus sp. n. is described and illustrated, a parasite of the coccinelid Harmonia axyridis Pallas, 1773 in a locality near Gran La Plata, Colonia Urquiza, Argentina. Of the 13 species described, this species,  it  is characterized by having a cephalic end projecting, faint stylet in its normal place, vulva posterior, tail appendage conoid, with bifurcated tip in both sexes, male with two spicules and a tiny gubernaculum, and leptoderan bursa. We obtained the 18S rDNA partial sequence.

The discovery of nematodes in spiders and scorpions from a manual sampling in the city of La Plata, Argentina, revealed the presence of specimens of the order Rhabditda. The main objective of this study is to present the presence of nematodes in the arachnid group, for which there is little precedent. One of the nematodes found belongs to the genus Rhabditis Dujardin, 1845, of saprophytic character, characterized by carrying a fungus that kills the host and degrades it in order to feed itself. This was found in the general cavity of the body of the spider Dysdera crocata Koch, 1838. It is characterized by having a thin cuticle, closed labial papillae, a long stoma without teeth, an esophagus with a middle bulb with a valve and a valved basal bulb, and a middle vulva, short and conical caudal appendage. Mitotic division is described and information about the morphology of chromosomes is p...

For the first time in Argentina, we report that in Harmonia axyridis Pallas, 1773, and Cycloneda sanguinea (Linnaeus, 1763) (Coleoptera, Coccinellidae) parasitizing by nematodes which belong to the family of Allantonematidae (Nematoda, Tylenchida). The genera are Metaparasitylenchus Wachek, 1955 (Nickle, 1967), Sulphuretylenchus Rühm, 1956 (Nickle, 1967) and Contortylenchus Rühm, 1956. They will be described and photographied afterwards.

For the first time in Argentina, we report that in Harmonia axyridis Pallas, 1773, and Cycloneda sanguinea (Linnaeus, 1763) (Coleoptera, Coccinellidae) parasitizing by nematodes which belong to the family of Allantonematidae (Nematoda, Tylenchida). The genera are Metaparasitylenchus Wachek, 1955 (Nickle, 1967), Sulphuretylenchus Rühm, 1956 (Nickle, 1967) and Contortylenchus Rühm, 1956. They will be described and photographied afterwards.